Tag Archive for 'Mapping'

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A year ago or so, we added a Google Map to a website friends of me are running. The website is about reptiles and amphibians. In one part of the site users can enter details into a form, including the location, when they’ve seen an interesting species. In the meantime their database has grown to a comprehensive collection of (crowd sourced) information like species distribution among our country. It’s not only a hobbyist project, the database means quite a valuable input for species research and protection projects too.

Anyways, before we added a Google Map to the form, user provided location information was very poor. Only a rough location description or coordinate information based on the national topographical map were possible to enter. For national coordinates users had to go to another website, look up the place and copy and paste the coordinates from there back into the form. Definitely not what I would call a convenient solution.

Once we added Google Maps where users could simply pinpoint the location on a map, the collected data turned into something like this:

Green dots … located with Google Maps (92%)
Red dots … located with a service of our National Mapping Agency (8%)

That says something about the benefit of public available mapping APIs. Especially for projects like this, with no commercial but a strong public interest.

Ordnance Survey heads into a good direction by releasing OpenSpace. OpenSpace is a mapping API, based on public geodata and OpenLayers, the Open Source JavaScript library for mapping. OS is probably the most progressive European mapping agency, so there is hope that others will follow (once they have all fulfilled INSPIRE and are done with metadata updates). It took some time until maps showed up at public authorities’ websites, followed by interactive maps and nowadays you even find WMS here and there. The next evolutionary step is probably public geodata made available through APIs.

During the INSPIRE process it became pretty clear that European mapping agencies don’t favor free public geodata. The API concept could help here: it enables flexible usage of data for users while retaining full control over both, functionality and data, for the mapping agency. Seems like a workable compromise to me.

I totally missed that it’s allowed in OpenStreetMap to derive vector data from aerial imagery provided by Yahoo! Maps. Apparently already since December 2006.

Last weekend, when we checked Vienna on OSM, we started wondering how come that it’s suddenly so rich on details. Did we miss a local GPS boom or mapping party?

The last time, it was summer, I collected and edited some tracks in my neighborhood for OSM, Vienna was poorly covered. Some major roads showed up and only a few neighborhoods were mapped more detailed (including parks, cemeteries or water areas for instance).

I didn’t know then that I can actually use the aerial imagery to refine my tracks and relied on the data my GPS unit returned. Reception and therefore accuracy in dense urban areas and narrow streets isn’t the best as you can imagine. Some of my tracks were way off and it was quite a hassle to put them in JOSM to a valid street network together.

However, the boost the Yahoo! aerial imagery gave OSM is impressive. Most parts of the central Viennese districts are already well covered. No wonder, it’s very easy to edit without the need of previously generated GPS tracks, directly via the browser interface.

The Russian developer Alexey “Holyfoot” Botchkov improved MySQL’s built-in GIS functions in order to use precise operations instead of MBR-based operations. Binary packages of a MySQL release containing his work are available for public testing here (FTP).

According to the GIS Functions wiki entry following MySQL GIS functions have been added to the MySQL 5.1.23 beta GIS release:

BUFFER

DIFFERENCE

DISTANCE

INTERSECTION

SYM_DIFFERENCE

UNION

I haven’t had the chance to test it yet, but I remember being very excited when I first read about the MySQL spatial extension a couple of years ago, followed by disappointment because of the MBR limits. Finally I decided to go with PostgreSQL/PostGIS back then.

However, if this functions make it into the official release it would be a good tool for proper storage and inclusion of geospatial data in (lightweighted) mapping applications like map mashups, compared to file based XML (KML) storage for instance. MySQL is supported by every other shared hosting plan, so the install base would be quite considerable I guess. [via heise]

Mapping and copyrights are two topics traditionally connected very strongly together. At least here in good old Europe people act very sensitive when re-publishing third party maps. Reading a couple of posts about Yahoo!’s new MapMixer, I started wondering how they would deal with that issue. On O’Reilly Radar I found an embedded MapMixer map containing a third party overlay clearly indicating “All rights reserved”. So maybe Brady Forrest actually holds the copyright, has the permission to redistribute or just missed the line

… Don’t upload any map or image that you don’t have the right to distribute …

when he uploaded the map below to Yahoo!’s MapMixer (assuming that it was him who added the map).

MapMixer is indeed an interesting service, but it’s really hard to find a copyright-free map. Except the ones available on Wikipedia. At least I couldn’t find any, neither do I own as person the copyrights of a map laying around here.

However, in many cases copyright holders won’t bother. And in many cases the service does make sense, like publishing a detailed campus map embedded in the Yahoo! street map to guide visitors.

But I doubt that most mapping agencies and map publishers will be very happy to see their maps popping up at Yahoo!. For instance, if I’d like to make a thousand black&white paper copies of the Austrian topographic map, I’d have to ask permission to do so. For publishing the same base map as image online, what MapMixer basically offers, one has to license the map for redistribution.

Regarding maps, I’d consider the potential user base for this service as rather low. But luckily MapMixer isn’t limited to maps only, users can upload any possible image and put it on the map. So it’ll be interesting to see what finally comes out.

A discussion yesterday made me think of how you can possibly prepare a mapping site to fulfill WAI standards.

Naturally any map produced by a map server comes as image. So the focus on improving accessibility on a mapping site will be to make images better accessible. One step is to improve map graphics and visualization such as contrast, color saturation, color scheme, strokes, etc., something cartographers are well aware about.

In addition to graphic qualities, another WAI requirement is to provide text equivalents for any non-text element, such as images are. A descriptive list, containing the main map elements like places, roads, rivers, mountains, etc. or even a statistical layers could be given as alternative output easily from any map server I’d suppose.

A more advanced solution would be an intelligent textual map output. Not only listing map elements but describing topography, relations among map elements and thematic layers. As if you would give an interpretation of the map to somebody else.

A quick research regarding mapping and accessibility didn’t lead me to much information. Besides, every mapping site I tried, failed Cynthia really badly (even this simple text-based site btw, maybe I should switch templates).

I know, SVG always has been the next big thing and never really took off, but in terms of web accessibility and mapping it offers the important ‘desc’ element:

Each container element or graphics element in an SVG drawing can supply a ‘desc’ and/or a ‘title’ description string where the description is text-only.

The ‘desc’ element basically allows you to provide textual information attached to every map element and deploy that way an (hidden) alternative textual map in addition to every map image. Clearly a major advantage of SVG over raster graphics regarding web accessibility.

For a business entity user, the Software may be used by you and your employees for internal use…

First of all, this is excellent news for GIS professionals. Ok, but what exactly does “internal use” mean? Our IT staff is now allowed to install Google Earth by default on any business PC and Laptop. I’d assume our employees can then legally use Google Earth for preparing business trips for instance.

But how far does “internal use” go when it comes to enterprise GIS support?

Available tools like Arc2Earth make GIS result presentation in Google Earth very easy and convenient. Instead of setting up map servers, where employees explore GIS results in web browsers, an internal enterprise information strategy could shift to Google Earth as client and KML as data storage (cf. Brian Timoneys smart KML S3 solution). Would that be considered as “internal use” by Google?

Imagine the GIS department of the city of Vienna serving their data as KML to Google Earth clients on 12.000 internal workstations across the city administration. Basically it’s internal use, but I’d assume such an “internal use” would probably upset Google.

Clearly, I’m now allowed to run Google Earth on my business PC, but, as GIS professional, I’m still not sure if I can consider it as possible way to go for “internal” data dissemination strategies.

Not only Vienna is heating up this week, we’re heading towards 35°C and more every day, no, even mapping sites are called hot today:
Microsoft released their research project Virtual Earth Hotmap.

Hotmap gives some insights about place popularity and shows where people have looked during the past 6 months in Virtual Earth.

It’s quite interesting that the map, the overall picture, is similar to other (spatial) analysis results we do in our day-to-day job: the map, literally based on hits and page impressions, shows an urban/rural divide and structures along major transport axis. Besides large urban areas, some tourism regions can be identified too – lake regions in Carinthia, skiing regions in Salzburg and Tyrol.

After a quick look at Virtual Earth Hotmap I’d say it provides some interesting data for regional marketing purposes and could be used additionally to other (tourism) website traffic analysis. E.g. if a tourism region doesn’t show up in Hotmap then probably not too many people are looking for information about or even searching directions to it (and going there?).

Today I’ve found a solution how to stay up to date where all the young hip people are going out in Vienna: it’s easy, just follow the “bobo” tag on Tupalo!

Tupalo is a Vienna based mapping-”Stuff in your Neighborhood”-start-up, a social networking site where people can easily pin-point their favorite spots on a map, rate and review them and share experiences. I started liking it mainly because it reminded me of a couple of nice places I went once, but for some reasons forgot about them and never came back again. So Tupalo is responsible for my quite long wanna-go-again list.

Among other features users can subscribe to all kinds of feeds on Tupalo. What I did to catch up with the local hip crowd is to subscribe to the bobo-RSS-feed. Since Tupalo is a mapping application, the RSS feed is of course GeoRSS flavored and can be placed immediately on a map. Each time a new hot bobo venue pops up in Vienna, I’ll get informed what and where it is right away! Great!

Somehow it reminds me of Amazon A9′s ambitious street views, seen a couple of years ago. Unlike Amazon, who only had street views available if I recall correctly, Google can offer this nice feature, which definitely provides very helpful information for travelers finding a particular place in an unknown area, as addition to already existing mapping features. That way they can easily evaluate user acceptance and benefit of the new 3D-like feature and decide later if they’re going to extend it to more cities.

The main advantage over Virtual Earth 3D is probably that Google’s Street View doesn’t ask – assuming an available Flash plugin – for installing any additional program. [via TechCrunch]

As Alex yesterday mentioned, the documents, as well as the documents referred to, lack of declaring a reference system. It’s quite obvious, and has been already discussed in the geo microformat BOF, that the coordinates enclosed by the “geo” tag are based on WGS84.

How come that WGS84 didn’t make it into the document then? I think an “open standard specification” must not allow any room for misinterpretations and therefore should include the declaration of the applied geographic reference system in some section.

…it works in Google Maps, so it seems to be right…

Ouch.

Why is defining a reference system important?

Once you leave Google Maps behind and try to visualize your geographic information in other mapping applications, such as national mapping services based on national reference systems others than WGS84 for instance, you should tell those applications about the framework you used to identify your locations. Otherwise you’ll run into troubles regarding the accuracy of your locations.

Austria is a small country but the national reference system includes 3 different prime meridians. In order to achieve satisfying mapping results you’ll always choose the closest meridian to your mapping area. Without the information which meridian was used for data collection for instance, you’ll end up having at least 3 options where your locations could be.

No serious web developer would ever write an HTML-document without a valid Document Type Declaration. It’s quite similar in geodesy with geographic data and reference systems. Would be great to see neogeographers fulfill minimum geodesy requirements. Geography is for some time around now and things like reference systems have turned out to be very useful.